browserName=navigator.appName; 
browserVer=parseInt(navigator.appVersion);

  if ((browserName=="Netscape" && browserVer>=3) || (browserName=="Microsoft Internet Explorer" && browserVer>=4))    
  version="n3";
  else
    version="n2";

  if (version=="n3")
   {

     pic1on= new Image();
     pic1on.src="images/topnav/tnav_assoccalendar_on.gif";  
     pic2on= new Image(); 
     pic2on.src="images/topnav/tnav_programscalendar_on.gif"; 
     pic3on= new Image(); 
     pic3on.src="images/topnav/tnav_sheltercove_on.gif"; 
     pic4on= new Image(); 
     pic4on.src="images/topnav/tnav_jarviscalendar_on.gif"; 
     
     pic1off= new Image();
     pic1off.src="images/topnav/tnav_assoccalendar_off.gif";  
     pic2off= new Image(); 
     pic2off.src="images/topnav/tnav_programscalendar_off.gif"; 
     pic3off= new Image(); 
     pic3off.src="images/topnav/tnav_sheltercove_off.gif"; 
     pic4off= new Image(); 
     pic4off.src="images/topnav/tnav_jarviscalendar_off.gif"; 

   }

function lightup(imgName)
 {
   if (version=="n3")
    {
      imgOn=eval(imgName + "on.src");
      document[imgName].src= imgOn;
    }
 }

function turnoff(imgName)
 {
   if (version=="n3")
    {
      imgOff=eval(imgName + "off.src");
      document[imgName].src= imgOff;
    }
 }